Light-emitting device, method for manufacturing the same, and electronic apparatus

ABSTRACT

The present invention provides a light-emitting device including a light-emitting element over a substrate, the light-emitting element is partitioned from an adjacent light-emitting element by a partition wall, the light-emitting element comprising a first electrode, a layer formed over the first electrode, a light-emitting layer formed over the layer and a second electrode formed over the light-emitting layer, the layer contains an inorganic compound, an organic compound and a halogen atom, the partition wall contains the inorganic compound and the organic compound, and the layer. The light-emitting device provides higher reliability and fewer defects.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light-emitting device, a method formanufacturing the same, and an electronic apparatus.

2. Description of the Related Art

In recent years, research and development have been actively conductedon light-emitting elements using electroluminescence. In a basicstructure of such a light-emitting element, a layer containing asubstance with a light-emitting property is interposed between a pair ofelectrodes. By application of a voltage to this element, light emissioncan be obtained from a substance with a light-emitting property.

This kind of light-emitting element, which is a self-luminous element,is advantageous in that pixel visibility is high compared to that of aliquid crystal display, that no backlight is needed, and the like andthought to be suitable for use as a flat panel display element. Inaddition, this kind of light-emitting element is highly advantageous inthat it can be fabricated to be thin and lightweight. Furthermore,response speed being extremely fast is one of the characteristics, aswell.

Moreover, because such a light-emitting element can be formed into afilm shape, by formation of an element with a large area, surfaceemission can easily be achieved. Because this characteristic isdifficult to achieve with point light sources represented byincandescent light bulbs and LEDs or with line light sources representedby fluorescent lamps, the utility value for surface light sources, whichcan be applied to lighting and the like, is high.

Light-emitting elements using electroluminescence are broadly classifiedaccording to whether a substance with a light-emitting property is anorganic compound or an inorganic compound.

When a substance with a light-emitting property is an organic compound,electrons and holes are injected into a layer containing an organiccompound with a light-emitting property from a pair of electrodes byapplication of a voltage to a light-emitting element, and then a currentflows therethrough. Recombination of electrons and holes (i.e.,carriers) places the organic compound with a light-emitting property inan excited state. The organic compound with a light-emitting propertyreturns to a ground state from the excited state, thereby emittinglight. Based on this mechanism, such a light-emitting element is calleda current excitation type light-emitting element.

The excited state generated by an organic compound can be a singletexcited state or a triplet excited state. Luminescence from the singletexcited state is referred to as fluorescence, and luminescence from thetriplet excited state is referred to as phosphorescence.

When such a light-emitting element is used for a display mode such as adisplay, a partition wall made of an insulator is typically providedbetween each pixel. By covering an edge portion of an electrode over asubstrate by a partition wall, short circuit between electrodes isprevented. However, if the inclination angle of this partition wall islarge, the film thickness of an organic film in a pixel is uneven andpeeling occurs between films, which results in a problem called a shrinkthat is a reduction in light-emitting region of a pixel. A reduction ina light-emitting region greatly decreases the reliability of alight-emitting element.

Further, other causes of short circuit between electrodes include fineparticles or the like which remain over the electrode. Because adistance between electrodes of a light-emitting element is usually about0.1 μm, even a fine particle of about 0.1 μm may easily cause shortcircuit between electrodes. A light-emitting element in which shortcircuit occurs between electrodes cannot emit light and is recognized asa dark spot. When a light-emitting element is used as a flat paneldisplay element, such a defect reduces the commercial value of a displaypanel, which results in an increase in panel cost.

One of methods for preventing short circuit between electrodes which iscaused by fine particles or the like is to increase the film thicknessof a buffer layer. Unfortunately, however, an increase in film thicknessof a buffer layer increases power consumption of a light-emittingelement because the conductivity of an organic compound is generallylow.

SUMMARY OF THE INVENTION

In view of the foregoing problems, it is an object of the presentinvention to provide a light-emitting device with higher reliability andfewer defects. Further, it is another object of the present invention isto provide a method for manufacturing the light-emitting device withhigher reliability and fewer defects. Further, it is still anotherobject of the present invention is to provide an electronic apparatushaving a light-emitting device with higher reliability and fewerdefects.

As a result of diligent study, the present inventors have found that astructure of a light-emitting element in which a partition wall and abuffer layer have the same film thickness or almost the same filmthickness is greatly effective in inhibiting a shrink. In addition, thepresent inventors have found that the structure is also effective insuppressing a defect because the film thickness of the buffer layer canbe increased.

One aspect of the present invention is a light-emitting device includinga plurality of light-emitting elements over a substrate; the pluralityof light-emitting elements is partitioned from adjacent light-emittingelement by a partition wall; the light-emitting element includes a firstelectrode, a buffer layer formed over the first electrode, alight-emitting layer formed over the buffer layer, and a secondelectrode formed over the light-emitting layer; and the buffer layer andthe partition wall have the same film thickness or almost the same filmthickness.

In the above structure, each of the buffer layer and the partition wallpreferably has a thickness of 500 nm or more because the partition wallis needed to cover a wiring or the like. The thickness of 500 nm or moreenables the buffer layer to cover fine particles even if fine particlesremain over the first electrode, whereby occurrence of short circuit canbe inhibited.

Further, in the above structure of the light-emitting device, the bufferlayer and the partition wall contain the same kind of inorganic compoundand the same kind of organic compound, and the buffer layer furthercontains a simple substance of a halogen.

It is to be noted that, the above structure is effective particularlyfor the case where the first electrode is electrically connected to athin film transistor formed over the substrate.

Another aspect of the present invention is a method for manufacturing alight-emitting device which includes the steps of forming a firstelectrode over a substrate, forming a layer containing an inorganiccompound and an organic compound so as to cover the first electrode,forming a buffer layer and a partition wall by selective addition of asimple substance of a halogen to a region located over the firstelectrode in the layer containing an inorganic compound and an organiccompound, forming a light-emitting layer over the region to which thesimple substance of a halogen is added, and forming a second electrodeover the light-emitting layer.

Still another aspect of the present invention is a method formanufacturing a light-emitting device which includes the steps offorming a plurality of thin film transistors over a substrate, forming afirst electrode so as to be electrically connected to the thin filmtransistors, forming a layer containing an inorganic compound and anorganic compound so as to cover the first electrode, forming a bufferlayer and a partition wall by selective addition of a simple substanceof a halogen to a region located over the first electrode in the layercontaining an inorganic compound and an organic compound, forming alight-emitting layer over the region to which the simple substance of ahalogen is added, and forming a second electrode over the light-emittinglayer.

In the above structure, the method for manufacturing a light-emittingdevice can be carried out without exposure to air after the layercontaining an inorganic compound and an organic compound is formed.

It is to be noted that the category of a light-emitting device in thisspecification includes image display apparatuses and light sources(e.g., lighting apparatuses). Further, the category of thelight-emitting device also includes modules in each of which a connectorsuch as a flexible printed circuit (FPC), a tape automated bonding (TAB)tape, or a tape carrier package (TCP) is attached to a panel; modules ineach of which a printed wiring board is provided at an end of a TAB tapeor a TCP; and also modules in each of which an integrated circuit (IC)is directly mounted on a light-emitting element by a chip on glass (COG)method.

Furthermore, the present invention also covers an electronic apparatusincluding the light-emitting device of the present invention.

In the present invention, the buffer layer and the partition wall havethe same film thickness or almost the same film thickness, and this filmthickness can be increased; accordingly, a light-emitting device withhigher reliability and fewer defects can be provided.

Since patterning of a partition wall by photolithography is not requiredin the present invention, the number of mask steps in the fabrication ofthe substrate is reduced; therefore, a light-emitting device can beprovided at low cost.

For a material of a partition wall, an organic material is typicallyused. At the same time, a partition wall of an organic material easilyabsorbs moisture; therefore, it is necessary that the partition wall beheated to remove moisture before formation of a light-emitting layer orthe like. However, even if the partition wall is heated, moisture in thepartition wall is not completely removed in some cases. This moisturepenetrates into the light-emitting layer, which may lead todeterioration of an element. In the present invention, since the stepsup to sealing can be performed without exposure to air after a partitionwall is formed, moisture hardly penetrates into a light-emitting layeror the like, and thus a highly reliable light-emitting device can beprovided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a light-emitting device of the present invention.

FIGS. 2A and 2B illustrate a method for manufacturing a light-emittingdevice of the present invention.

FIGS. 3A and 3B illustrate a method for manufacturing a light-emittingdevice of the present invention.

FIGS. 4A and 4B illustrate a method for manufacturing a light-emittingdevice of the present invention.

FIGS. 5A and 5B illustrate a light-emitting device of the presentinvention.

FIGS. 6A to 6D illustrate electronic apparatuses of the presentinvention.

FIG. 7 illustrates an electronic apparatus of the present invention.

FIG. 8 illustrates a lighting apparatus of the present invention.

FIG. 9 illustrates a lighting apparatus of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiment modes of the present invention are describedusing the accompanying drawings. It is to be noted that the presentinvention is not limited to the description below and that a variety ofchanges may be made in forms and details without departing from thespirit and the scope of the present invention. Therefore, the presentinvention should not be limited to the description of the embodimentmodes below.

Embodiment Mode 1

In this embodiment mode, a light-emitting device of the presentinvention and a method for manufacturing the light-emitting device aredescribed using FIG. 1.

The light-emitting device has a light-emitting element in which aplurality of layers is stacked between a pair of electrodes. Theplurality of layers is formed by combining and stacking a layer formedof a substance with a high carrier-injecting property and a layer formedof a substance with a high carrier-transporting property so that alight-emitting region is formed apart from the electrodes, in otherwords, carriers are recombined in a portion apart from the electrodes.In the light-emitting device of the present invention, a plurality oflight-emitting elements is provided, and a partition wall 104 isprovided between the light-emitting elements.

In this embodiment mode, the light-emitting element includes a firstelectrode 102, a second electrode 108, a buffer layer 103, ahole-transporting layer 105, a light-emitting layer 106, and anelectron-transporting layer 107. In the description below of thisembodiment mode, it is assumed that the first electrode 102 functions asan anode and that the second electrode 108 functions as a cathode. Inother words, hereinafter, it is assumed that light emission can beobtained when a voltage is applied to the first electrode 102 and thesecond electrode 108 so that a potential of the first electrode 102 ishigher than that of the second electrode 108.

A substrate 101 is used as a support of the light-emitting element. Forthe substrate 101, glass, plastic, or the like, for example, can beused. It is to be noted that any material other than these may be usedas long as it functions as the support in a fabrication process of thelight-emitting element.

Preferably, the first electrode 102 is formed using any of metals,alloys, or conductive compounds, a mixture thereof or the like with ahigh work function (specifically, a work function of 4.0 eV or higher ispreferable). Specifically, indium tin oxide (ITO), indium tin oxidecontaining silicon or silicon oxide, indium zinc oxide (IZO), indiumoxide containing tungsten oxide and zinc oxide (IWZO), and the like aregiven, for example. Films of such conductive metal oxides are typicallyformed by sputtering, but may also be formed by application of a sol-gelprocess or the like. For example, a film of an indium zinc oxide (IZO)can be formed using a target in which 1 wt % to 20 wt % zinc oxide isadded to indium oxide by a sputtering method. A film of indium oxidecontaining tungsten oxide and zinc oxide (IWZO) can be formed using atarget in which 0.5 wt % to 5 wt % tungsten oxide and 0.1 wt % to 1 wt %zinc oxide are added to indium oxide by a sputtering method.Alternatively, gold (Au), platinum (Pt), nickel (Ni), tungsten (W),chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu),palladium (Pd), a nitride of a metal material (e.g., titanium nitride),or the like can be used.

When a layer containing an inorganic compound and an organic compound,which is described later, is used as a layer in contact with the firstelectrode 102, any of a variety of metals, alloys, or conductivecompounds, a mixture thereof, or the like can be used for the firstelectrode 102 regardless of the work function. For example, aluminum(Al), silver (Ag), an alloy containing aluminum, or the like can beused. Alternatively, it is possible to use any of elements belonging toGroup 1 and 2 of the periodic table, that is, alkali metals such aslithium (Li) and cesium (Cs), alkaline earth metals such as magnesium(Mg), calcium (Ca), and strontium (Sr), alloys containing them (e.g.,MgAg and AlLi), rare earth metals such as europium (Eu) and ytterbium(Yb), alloys containing them, and the like which are materials with alow work function. Films of alkali metals, alkaline earth metals, andalloys thereof can be formed by a vacuum evaporation method.Alternatively, films of alloys containing alkali metals or alkalineearth metals can also be formed by a sputtering method. Furtheralternatively, such films can be formed using a silver paste by adroplet discharging method or the like.

According to one feature of the present invention, the buffer layer 103and the partition wall 104 have the same film thickness or almost thesame film thickness. Thus, surfaces of the buffer layer and thepartition wall are almost flat, and the hole-transporting layer 105, thelight-emitting layer 106, and the like formed over the buffer later canbe formed to be flat. Thus, each of the hole-transporting layer 105, thelight-emitting layer 106, and the like hardly has an uneven filmthickness in a pixel, and peeling hardly occurs between the layers aswell.

Further, the film thickness of the buffer layer 103 is desirablyincreased in order to suppress short circuit between the electrodes,which results from fine particles or the like remaining over the anode.In order to increase the film thickness, it is necessary that the bufferlayer 103 be highly conductive. Accordingly, in particular, a filmformed by addition of simple substance of a halogen to a mixed film ofan inorganic compound and an organic compound is used for the bufferlayer 103 in the present invention.

Transition metal oxides can be used as the inorganic compound used forthe buffer layer 103. Alternatively, oxides of metals that belong toGroup 4 to Group 8 of the periodic table can be used. Specifically, useof vanadium oxide, niobium oxide, tantalum oxide, chromium oxide,molybdenum oxide, tungsten oxide, manganese oxide, or rhenium oxide ispreferable because of their high electron accepting properties. Inparticular, use of molybdenum oxide is preferable because of itsstability in air, a low hygroscopic property, and ease of handling.Alternatively, use of molybdenum trioxide is further preferable.

As the organic compound used for the buffer layer 103, any of a varietyof compounds such as an aromatic amine compound, a carbazole derivative,an aromatic hydrocarbon, an oligomer, a dendrimer, or a polymer can beused. It is to be noted that as the organic compound used for the bufferlayer, a compound with a high hole-transporting property (hereinafter,referred to as a hole-transporting material) is preferably used.Specifically, a substance having a hole mobility of 10⁻⁶ cm²/(V·s) ormore is preferably used. However, any substance other than the abovesubstances may also be used as long as it is a substance in which thehole-transporting property is higher than the electron-transportingproperty. Hereinafter, organic compounds that can be used for the bufferlayer 103 are specifically described.

Examples of the aromatic amine compounds includeN,N′-di(p-tolyl)-N,N′-diphenyl-p-phenylenediamine (abbreviated toDTDPPA), 4,4′-bis[N(4-diphenylaminophenyl)-N-phenylamino]biphenyl(abbreviated to DPAB),4,4′-bis(N-{4-[N′,N′-bis(3-methylphenyl)aminophenyl]-N-phenyl}amino)biphenyl(abbreviated to DNTPD),1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviatedto DPA3B), and the like.

Examples of the carbazole derivatives that can be used for the bufferlayer 103 include3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole(abbreviated to PCzPCA1),3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole(abbreviated to PCzPCA2),3-[N-(1-naphtyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole(abbreviated to PCzPCN1), and the like.

Moreover, 4,4′-di(N-carbazolyl)biphenyl (abbreviated to CBP),1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviated to TCPB),9-[4-(N-carbazolyl)phenyl]-10-phenylanthracene (abbreviated to CzPA),1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, or the likecan be used.

Examples of the aromatic hydrocarbons that can be used for the bufferlayer 103 include 2-tert-butyl-9,10-di(2-naphthyl)anthracene(abbreviated to t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene,9,10-bis(3,5-diphenylphenyl)anthracene (abbreviated to DPPA),2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviated tot-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviated to DNA),9,10-diphenylanthracene (abbreviated to DPAnth), 2-tert-butylanthracene(abbreviated to t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene(abbreviated to DMNA),2-tert-butyl-9,10-bis[2-(1-naphthyl)phenyl]anthracene,9,10-bis[2-(1-naphthyl)phenyl]anthracene,2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene,2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9′-bianthryl,10,10′-diphenyl-9,9′-bianthryl,10,10′-bis(2-phenylphenyl)-9,9-bianthryl, 10,10′-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9-bianthryl, anthracene, tetracene,rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, and the like.Besides these compounds, pentacene, coronene, or the like canalternatively be used. As described above, use of an aromatichydrocarbon which has a hole mobility of 1×10⁻⁶ cm²/(V·s) or more andhas 14 to 42 carbon atoms is more preferable.

It is to be noted that the aromatic hydrocarbons which can be used forthe buffer layer 103 may have a vinyl skeleton. Examples of the aromatichydrocarbons having a vinyl skeleton include4,4′-bis(2,2-diphenylvinyl)biphenyl (abbreviated to DPVBi),9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviated to DPVPA),and the like.

Furthermore, a high molecular compound such as poly(N-vinylcarbazole)(abbreviated to PVK), poly(4-vinyltriphenylamine) (abbreviated toPVTPA),poly[N-(4-{N′-[4-(4-diphenylamino)phenyl]phenyl-N′-phenylamino}phenyl)methacrylamide](abbreviated to PTPDMA), orpoly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine] (abbreviated toPoly-TPD) can be used.

Examples of the simple substance of a halogen which can be used for thebuffer layer 103 include fluorine, chlorine, iodine, bromine, and thelike, and use of fluorine or chlorine is preferable in particular.

In addition, the partition wall 104 is formed using a mixed film of aninorganic compound and an organic compound which is also used for thebuffer layer 103.

In addition, because it is necessary that the buffer layer completelycover the fine particles remaining over the anode and that the partitionwall completely cover a wiring or the like, each of the buffer layer andthe partition wall preferably has a thickness of 500 nm or more.

A hole-transporting layer 105 is a layer that contains a substancehaving a high hole-transporting property. Examples of the substancehaving a high hole-transporting property include aromatic aminecompounds such as 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl(abbreviated to NPB),N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine(abbreviated to TPD), 4,4′,4″-tris(N,N-diphenylamino)triphenylamine(abbreviated to TDATA),4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine(abbreviated to MTDATA), and4,4′-bis[N-(spiro-9,9′-bifluoren-2-yl)-N-phenylamino]-1,1′-biphenyl(abbreviated to BSPB). These substances described here are mainlysubstances having a hole mobility of 10⁻⁶ cm²/Vs or more. However, anysubstance other than the above substances may also be used as long as itis a substance in which the hole-transporting property is higher thanthe electron-transporting property. The layer that contains a substancehaving a high hole-transporting property is not limited to a singlelayer and may be a stack of two or more layers each formed of theaforementioned substance.

For the hole-transporting layer, a high molecular compound such aspoly(N-vinylcarbazole) (abbreviated to PVK) orpoly(4-vinyltriphenylamine) (abbreviated to PVTPA) can alternatively beused.

The light-emitting layer is a layer that contains a substance with ahigh light-emitting property. As a substance with a high light-emittingproperty, a fluorescent compound that emits fluorescence or aphosphorescent compound that emits phosphorescence can be used.

As the phosphorescent compound that can be used for the light-emittinglayer, examples of a blue light-emitting material includebis[2-(4′,6′-difluorophenyl)pyridinato-N,C^(2′)]iridium(III)tetrakis(1-pyrazolyl)borate(abbreviated to FIr6),bis[2-(4′,6′-difluorophenyl)pyridinato-N,C^(2′)]iridium(III)picolinate(abbreviated to FIrpic),bis{2-[3′,5′-bis(trifluoromethyl)phenyl]pyridinato-N,C^(2′)}iridium(III)picolinate(abbreviated to Ir(CF₃ ppy)₂(pic)),bis[2-(4′,6′-difluorophenyl)pyridinato-N,C^(2′)]iridium(III)acetylacetonate(abbreviated to FIr(acae)), and the like. Examples of greenlight-emitting material include tris(2-phenylpyridinato-N,C^(2′))iridium(III) (abbreviated to Ir(ppy)₃), bis(2-phenylpyridinato-N,C^(2′))iridium(III)acetylacetonate (abbreviated to Ir(ppy)₂(acac)),bis(1,2-diphenyl-1H-benzimidazolato)iridium(III)acetylacetonate(abbreviated to Ir(pbi)₂(acac)),bis(benzo[h]quinolinato)iridium(III)acetylacetonate (abbreviated toIr(bzq)₂(acac)), and the like. Examples of a yellow light-emittingmaterial includebis(2,4-diphenyl-1,3-oxazolato-N,C²)iridium(III)acetylacetonate(abbreviated to Ir(dpo)₂(acac)),bis{2-[4′-(perfluorophenylphenyl)pyridinato-N,C^(2′)]iridium(III)acetylacetonate(abbreviated to Ir(p-PF-ph)₂(acac)), bis(2-phenylbenzothiazolato-N,C^(2′))iridium(III)acetylacetonate (abbreviated to Ir(bt)₂(acac)), andthe like. Examples of an orange light-emitting material includetris(2-phenylquinolinato-N, C^(2′))iridium(III) (abbreviated toIr(pq)₃), bis(2-phenylquinolinato-N,C^(2′))iridium(III)acetylacetonate(abbreviated to Ir(pq)₂(acac)), and the like. Examples of a redlight-emitting material include organic metal complexes such asbis(2-(2′-benzo[4,5-α]thienyl)pyridinato-N,C^(3′))iridium(III)acetylacetonate(abbreviated to Ir(btp)₂(acac)),bis(1-phenylisoquinolinato-N,C^(2′))iridium(III)acetylacetonate(abbreviated to Ir(piq)₂(acac)),(acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III)(abbreviated to Ir(Fdpq)₂(acac)), and2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine platinum(II) (abbreviatedto PtOEP). In addition, a rare-earth metal complex such astris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviated toTb(acac)₃(Phen)),tris(1,3-diphenyl-1,3-popanedionato)(monophenanthroline)europium(III)(abbreviated to Eu(DBM)₃(Phen)), ortris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III)(abbreviated to Eu(TTA)₃(Phen)) performs light emission (electrontransition between different multiplicities) from a rare-earth metalion; therefore, such a rare-earth metal complex can be used as thephosphorescent compound.

As the fluorescent compound which can be used for the light-emittinglayer, examples of a blue light-emitting material includeN,N′-bis[4-(9H-carbazol-9-yl)phenyl]-N,N′-diphenylstilbene-4,4′-diamine(abbreviated to YGA2S),4-(9H-carbazol-9-yl)-4′-(10-phenyl-9-anthryl)triphenylamine (abbreviatedto YGAPA), and the like. Examples of a green light-emitting materialinclude N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine(abbreviated to 2PCAPA),N-[9,10-bis(1,1′-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine(abbreviated to 2PCABPhA),N-(9,10-diphenyl-2-anthryl)-N,N′,N′-triphenyl-1,4-phenylenediamine(abbreviated to 2DPAPA),N-[9,10-bis(1,1′-biphenyl-2-yl)-2-anthryl]-N,N′,N′-triphenyl-1,4-phenylenediamine(abbreviated to 2DPABPhA),N-[9,10-bis(1,1′-biphenyl-2-yl)]-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracene-2-amine(abbreviated to 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviatedto DPhAPhA), and the like. Examples of a yellow light-emitting materialinclude rubrene, 5,12-bis(1,1′-biphenyl-4-yl)-6,11-diphenyltetracene(abbreviated to BPT), and the like. Examples of a red light-emittingmaterial includeN,N,N′,N′-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviated top-mPhTD),7,13-diphenyl-N,N,N′,N′-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine(abbreviated to p-mPhAFD), and the like.

For the electron-transporting layer 107, a substance with a highelectron-transporting property can be used. For example, theelectron-transporting layer 107 can be formed using a metal complex orthe like having a quinoline skeleton or a benzoquinoline skeleton, suchas tris(8-quinolinolato)aluminum (abbreviated to Alq),tris(4-methyl-8-quinolinolato)aluminum (abbreviated to Almq₃),bis(10-hydroxybenzo[h]quinolinato)beryllium (abbreviated to BeBq₂), orbis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum (abbreviated toBAlq). Alternatively, a metal complex or the like having anoxazole-based or thiazole-based ligand, such asbis[2-(2-hydroxyphenyl)benzoxazolato]zinc (abbreviated to Zn(BOX)₂) orbis[2-(2-hydroxyphenyl)benzothiazolato]zinc (abbreviated to Zn(BTZ)₂)can also be used. Instead of metal complexes,2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated toPBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene(abbreviated to OXD-7),3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole(abbreviated to TAZ), bathophenanthroline (abbreviated to BPhen),bathocuproine (abbreviated to BCP), or the like can alternatively beused. The substances described here are mainly substances each having anelectron mobility of 10⁻⁶ cm²/Vs or more. However, any substance otherthan the above substances may also be used as long as it is a substancein which the electron-transporting property is higher than thehole-transporting property. Furthermore, the electron-transporting layeris not limited to a single layer and may be a stack of two or morelayers each formed of the aforementioned substance.

For the electron-transporting layer 107, a high molecular compound canbe used. For example,poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)](abbreviatedto PF-Py),poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-bipyridine-6,6′-diyl)](abbreviated to PF-BPy), or the like can be used.

The second electrode 108 can be formed using a metal, an alloy, or aconductive compound, a mixture thereof, or the like with a low workfunction (specifically, 3.8 eV or lower). Specific examples of such amaterial with a low work function include elements belonging to Group 1and 2 of the periodic table, that is, alkali metals such as lithium (Li)and cesium (Cs), alkaline earth metals such as magnesium (Mg), calcium(Ca), and strontium (Sr), alloys containing them (e.g., MgAg and AlLi),rare earth metals such as europium (Eu) and ytterbium (Yb), alloyscontaining them, and the like. However, when a layer having a functionof promoting electron injection is provided between the second electrode108 and the electron-transporting layer, any of a variety of conductivematerials such as Al, Ag, ITO, and indium tin oxide containing siliconor silicon oxide can be used for the second electrode 108 regardless ofthe work function. Films of these conductive materials can be formed bya sputtering method, an inkjet method, a spin coating method, or thelike.

For the layer having a function of promoting electron injection, analkali metal, an alkaline earth metal, or a compound thereof such aslithium fluoride (LiF), cesium fluoride (CsF), or calcium fluoride(CaF₂) can be used. Alternatively, a layer formed of a substance with anelectron-transporting property which contains an alkali metal, analkaline earth metal, or a compound thereof, for example, a layer formedof Alq which contains magnesium (Mg), or the like can be used. It ismore preferable to use the layer formed of a substance with anelectron-transporting property which contains an alkali metal or analkaline earth metal because electron can be injected efficiently fromthe second electrode 108 by the use of such a layer.

Any of a variety of methods can be employed for forming the buffer layer103, the hole-transporting layer 105, the light-emitting layer 106, andthe electron-transporting layer 107 regardless of whether the method isa dry process or a wet process. For example, a vacuum evaporationmethod, an inkjet method, a spin-coating method, or the like may beemployed. Further, different formation methods may be employed for eachelectrode or layer.

Similarly, the electrodes may also be formed by a wet process such as asol-gel process or by a wet process using a paste of a metal material.Alternatively, the electrodes may also be formed by a dry process suchas a sputtering method or a vacuum evaporation method.

Light is extracted outside through one or both of the first electrode102 and the second electrode 108. Thus, one or both of the firstelectrode 102 and the second electrode 108 are light-transmittingelectrodes. When only the first electrode 102 is a light-transmittingelectrode, light is extracted from the substrate side through the firstelectrode 102. In contrast, when only the second electrode 108 is alight-transmitting electrode, light is extracted from a side opposite tothe substrate side through the second electrode 108. When both the firstelectrode 102 and the second electrode 108 are light-transmittingelectrodes, light is extracted from both the substrate side and the sideopposite to the substrate side through the first electrode 102 and thesecond electrode 108.

In this embodiment mode, the light-emitting element is fabricated over asubstrate formed of glass, plastic, or the like. In addition, forexample, a thin film transistor (TFT) may be formed over a substrateformed of glass, plastic, or the like, and a light-emitting element maybe fabricated over an electrode that is electrically connected to theTFT. Accordingly, an active matrix light-emitting device in which driveof the light-emitting element is controlled by a TFT can bemanufactured. It is to be noted that there is no particular limitationon the structure of the TFT. A staggered TFT or an inversely staggeredTFT may be used. Also, there is no particular limitation on thecrystallinity of a semiconductor that is to be used for the TFT, and anamorphous semiconductor or a crystalline semiconductor may be used.Alternatively, a single crystal semiconductor film may be used. A singlecrystal semiconductor film can be formed by Smart Cut (registeredtrademark) or the like. In addition, a driver circuit formed over a TFTsubstrate may include both an n-channel TFT and a p-channel TFT oreither an n-channel TFT or a p-channel TFT.

Embodiment Mode 2

In this embodiment mode, a method for forming a buffer layer 204 and apartition wall 205 as described in Embodiment Mode 1 is described. Asdescribed in Embodiment Mode 1, the buffer layer 204 and the partitionwall 205 have the same film thickness or almost the same film thickness.In addition, the buffer layer and the partition wall contains the samekind of organic compound and the same kind of inorganic compound, andthe buffer layer 204 further contains a simple substance of a halogen.

In FIGS. 2A and 2B, several divided first electrodes 202 are providedover a substrate 201. FIG. 2A is a cross-sectional view, and FIG. 2B isa top view. The first electrode 202 corresponds to each pixel and isdisposed in a pixel region 301. In the sealing region 302, a sealingmaterial is disposed so as to surround the pixel region. Desirably, noorganic material exists under the sealing material. In addition,desirably, no organic material exists in a contact portion 303 of thesecond electrode and the wiring.

In the above structure, a mixed film 203 of an inorganic compound and anorganic compound is formed so as to cover the entire pixel region asshown in FIGS. 3A and 3B. For formation of the mixed film 203, any of avariety of method can be employed regardless of whether the method is adry process or a wet process. As a dry process, a vacuum evaporationmethod, a sputtering method, or the like can be used. In addition, as awet process, an inkjet method, a spin coating method, a printing method,or the like can be used.

Preferably, the mixed film 203 covers the entire region except thesealing region and the contact portion of the second electrode and thewiring as shown in FIGS. 3A and 3B, because the mixed film 203 is alayer that is a basis for the buffer layer and the partition wall. Onthe other hand, when the mixed film 203 is extremely highly conductive,there is no problem caused by forming over the contact portion 303 ofthe second electrode and the wiring; thus, when the mixed film is formedover the contact portion 303 of the second electrode and the wiring, thesimple substance of a halogen is preferably added to the mixed filmlocated over the contact portion 303 of the second electrode and thewiring.

In the above structure, only the portion located over the firstelectrode is selectively to which the simple substance of a halogen isadded as shown in FIGS. 4A and 4B. By addition of the simple substanceof a halogen, the conductivity of the portion in the mixed film 203 towhich the simple substance of a halogen is added drastically improves.Accordingly, the region to which the simple substance of a halogen isadded functions as the buffer layer 204, and the region which is not towhich the simple substance of a halogen is added functions as thepartition wall 205. Thus, the buffer layer 204 and the partition wall205 have the same film thickness or almost the same film thickness.Specifically, a change in film thickness of the buffer layer is within±5% of film thickness of the mixed film measured before the addition ofthe simple substance of a halogen.

As a method for adding the simple substance of a halogen, an ionimplantation process is preferable. Partial implantation using a metalmask may be performed, and alternatively a single ion implantationprocess based on a convergent ion beam technique may be employed.

When the mixed film 203 itself is highly conductive, it is not suitablefor the partition wall 205; therefore, the mixture ratio of an inorganiccompound is preferably low. At the same time, mixture of an inorganiccompound is necessary because addition of the simple substance of ahalogen to only an organic compound has less effect on an improvement inconductivity. The weight percent of the inorganic compound in the mixedfilm is preferably greater than or equal to 5% and less than or equal to25%.

In addition, the concentration of a halogen atom contained in the bufferlayer is preferably 1×10²¹ atoms/cm³ or more. For example, although theresistivity of the mixed film containing NPB and molybdenum trioxide (afilm formed by a co-evaporation method so that the weight ratio is4:1=molybdenum trioxide:NPB) is 1.8×10⁹ Ω·cm, when addition of fluorineis performed at a concentration of 1×10²¹ atoms/cm³, the resistivity ofthe mixed film becomes 3.5×10⁵ Ω·cm.

In this mode, after the formation of the buffer layer 204 and thepartition wall 205, a light-emitting element can be fabricated withoutexposure of the substrate to air; thus, moisture does not easily enterthe light-emitting element, whereby a highly reliable light-emittingelement can be fabricated.

Embodiment Mode 3

In this embodiment mode, a light-emitting device of the presentinvention is described.

In this embodiment mode, the light-emitting device of the presentinvention is described using FIGS. 5A and 5B. FIG. 5A is a top view ofthe light-emitting device, and FIG. 5B is a cross-sectional view takenalong lines A-A′ and B-B′ of FIG. 5A. The light-emitting device has adriver circuit portion (a source side driver circuit) 601, a pixelportion 602, and a driver circuit portion (a gate side driver circuit)603 to control the light-emitting device, which are indicated by dottedlines. Reference numerals 604 and 605 denote a sealing substrate and asealing material, respectively. A portion enclosed by the sealingmaterial 605 corresponds to a space 607.

A lead wiring 608 is used to transmit signals to be inputted to thesource side driver circuit 601 and the gate side driver circuit 603 andreceives a video signal, a clock signal, a start signal, a reset signal,and the like from a flexible printed circuit (FPC) 609 which is anexternal input terminal. It is to be noted that only the FPC isillustrated in this case; however, the FPC may be provided with aprinted wiring board (PWB). The category of a light-emitting device inthis specification includes not only a light-emitting device itself butalso a light-emitting device to which an FPC or a PWB is attached.

Next, a cross-sectional structure is described using FIG. 5B. The drivercircuit portion and the pixel portion are formed over an elementsubstrate 610. In this case, one pixel in the pixel portion 602 and thesource side driver circuit 601 which is the driver circuit portion areillustrated.

A CMOS circuit, which is a combination of an n-channel TFT 623 and ap-channel TFT 624, is formed as the source side driver circuit 601. Eachdriver circuit portion may be any of a variety of circuits such as aCMOS circuit, a PMOS circuit, or an NMOS circuit. Although adriver-integration type device in which a driver circuit is formed overthe substrate where the pixel portion is formed is described in thisembodiment mode, a driver circuit is not necessarily be formed over thesubstrate where the pixel portion is formed but can be formed externallyfrom a substrate.

The pixel portion 602 is formed of a plurality of pixels each of whichincludes a switching TFT 611, a current control TFT 612, and a firstelectrode 613 which is electrically connected to a drain of the currentcontrol TFT 612. It is to be noted that a partition wall 614 is formedto cover end portions of the first electrode 613. For the partition wall614, as described in Embodiment Mode 1, a film formed of a mixture of aninorganic compound and an organic compound is used.

A buffer layer 619, an EL layer 616, and a second electrode 617 areformed over the first electrode 613. In this case, a material with ahigh work function is preferably used for the first electrode 613 thatfunctions as an anode. For example, it is possible to use a single-layerfilm of an ITO film, an indium tin oxide film containing silicon, anindium oxide film containing 2 wt % to 20 wt % zinc oxide, a titaniumnitride film, a chromium film, a tungsten film, a Zn film, a Pt film, orthe like; a stack of a titanium nitride film and a film containingaluminum as its main component; a three-layer structure of a titaniumnitride film, a film containing aluminum as its main component, and atitanium nitride film; or the like. It is to be noted that when astacked structure is employed, resistance as a wiring is low, a goodohmic contact is formed, and further, the first electrode 613 can bemade to function as an anode.

As described in Embodiment Mode 1, the buffer layer 619 is formed usinga film formed by addition of the simple substance of a halogen to a filmcontaining a mixture of an inorganic compound and an organic compoundwhich is also used for the partition wall 614.

The EL layer 616 is formed by any of a variety of methods such as anevaporation method using an evaporation mask, an inkjet method, and aspin coating method. The EL layer 616 includes a hole-transportinglayer, a light-emitting layer, and the like which are formed over thebuffer layer.

In the contact portion 620, the second electrode 617 is electricallyconnected to the wiring 621, Desirably, no organic compound exists inthe contact portion 620 as shown in FIGS. 5A and 5B.

For the second electrode 617 which is formed over the EL layer 616 andfunctions as a cathode, use of a material with a low work function(e.g., Al, Mg, Li, Ca, or an alloy or a compound thereof such as MgAg,Mgln, AlLi, LiF, or CaF₂) is preferable. It is to be noted that, whenlight emitted from the EL layer 616 is transmitted through the secondelectrode 617, the second electrode 617 is preferably formed using astack of a metal thin film with a reduced thickness and a transparentconductive film (e.g., ITO, indium tin oxide containing 2 wt % to 20 wt% zinc oxide, indium tin oxide containing silicon or silicon oxide, orzinc oxide (ZnO)).

The sealing substrate 606 is attached using the sealing material 605 tothe element substrate 610; thus, a light-emitting element 618 isprovided in the space 607 enclosed by the element substrate 610, thesealing substrate 606, and the sealing material 605. It is to be notedthat the space 607 is filled with a filler. The space 607 is filled withan inert gas (e.g., nitrogen or argon) or the sealing material 605 insome cases.

It is preferable that an epoxy-based resin be used to form the sealingmaterial 605 and that such a material permeate little moisture andoxygen as much as possible. Alternatively, the sealing substrate 604 canbe formed of a glass substrate, a quartz substrate, a plastic substratemade of fiberglass-reinforced plastic (FRP), polyvinyl fluoride (PVF),polyester, acrylic, or the like.

Accordingly, the light-emitting device of the present invention can beobtained.

The light-emitting device of the present invention employs the elementstructure described in Embodiment Mode 1, and thus a light-emittingdevice with good properties can be obtained. Specifically, alight-emitting device with higher reliability and fewer defects can beobtained.

Embodiment Mode 4

In this embodiment mode, an electronic apparatus of the presentinvention which has the light-emitting device described in EmbodimentMode 3 are described.

Examples of the electronic apparatus having the light-emitting device ofthe present invention include cameras such as video cameras or digitalcameras, goggle type displays, navigation systems, audio playbackdevices (e.g., car audio systems and audio systems), computers, gamemachines, portable information terminals (e.g., mobile computers,cellular telephones, portable game machines, and electronic books),image playback devices in which a recording medium is provided(specifically, devices that are capable of playing back recording mediasuch as digital versatile discs (DVDs) and equipped with a display unitthat can display the image), and the like. Specific examples of theseelectronic apparatuses are shown in FIGS. 6A to 6D.

FIG. 6A shows a television set according to the present invention whichincludes a housing 9101, a support stand 9102, a display portion 9103, aspeaker portion 9104, a video input terminal 9105, and the like. In thetelevision set, the display portion 9103 has a light-emitting devicesimilar to that described in Embodiment Mode 1. The light-emittingdevice has features of higher reliability and fewer defects. Since thedisplay portion 9103 having the light-emitting device has similarfeatures, the television set hardly deteriorates and has fewer defectsin image quality.

FIG. 6B shows a computer according to the present invention whichincludes a main body 9201, a housing 9202, a display portion 9203, akeyboard 9204, an external connection port 9205, a pointing device 9206,and the like. In the computer, the display portion 9203 has alight-emitting device similar to that described in Embodiment Mode 1.The light-emitting device has features of higher reliability and fewerdefects. Since the display portion 9203 having the light-emitting devicehas similar features, the computer hardly deteriorates and has fewerdefects in image quality.

FIG. 6C shows a cellular telephone according to the present inventionwhich includes a main body 9601, a housing 9602, a display portion 9603,an audio input portion 9604, an audio output portion 9605, operationkeys 9606, an external connection port 9607, an antenna 9608, and thelike. In the cellular telephone, the display portion 9603 has alight-emitting device similar to that described in Embodiment Mode 1.The light-emitting device has features of higher reliability and fewerdefects. Since the display portion 9403 having the light-emitting devicehas similar features, the cellular telephone hardly deteriorates and hasfewer defects in image quality.

FIG. 6D shows a camera according to the present invention which includesa main body 9501, a display portion 9502, a housing 9503, an externalconnection port 9504, a remote control receiver 9505, an image receiver9506, a battery 9507, an audio input portion 9508, operation keys 9509,an eye piece portion 9510, and the like. In the camera, the displayportion 9502 has a light-emitting device similar to that described inEmbodiment Mode 1. The light-emitting device has features of higherreliability and fewer defects. Since the display portion 9502 having thelight-emitting device has similar features, the camera hardlydeteriorates and has fewer defects in image quality.

As described above, the applicable range of the light-emitting device ofthe present invention is extremely wide so that this light-emittingdevice can be applied to electronic apparatuses of a variety of fields.By use of the light-emitting device of the present invention, anelectronic apparatus having a display portion with higher reliabilityand fewer defects can be provided.

Such a light-emitting device of the present invention can also be usedas a lighting apparatus. One mode in which the light-emitting device ofthe present invention is used for a lighting apparatus is describedusing FIG. 7.

FIG. 7 shows an example of a liquid crystal display device in which thelight-emitting device of the present invention is used as a backlight.The liquid crystal display device shown in FIG. 7 includes a housing901, a liquid crystal layer 902, a backlight 903, and a housing 904. Theliquid crystal layer 902 is connected to a driver IC 905. Thelight-emitting device of the present invention is used as the backlight903, and a current is supplied through a terminal 906.

With the light-emitting device of the present invention used as thebacklight of the liquid crystal display device, a backlight with higherreliability and fewer defects can be obtained. Since the light-emittingdevice of the present invention is a lighting apparatus with plane lightemission and can be made to have a larger area, the backlight can bemade to have a larger area, and a liquid crystal display device can alsobe made to have a larger area as well. Furthermore since thelight-emitting device of the present invention is thin, a thinner shapeof a display device can also be achieved. Further still, since thelight-emitting device of the present invention has higher reliabilityand fewer defects, a liquid crystal display device in which thelight-emitting device of the present invention is used has higherreliability and fewer defects as well.

FIG. 8 shows an example in which the light-emitting device to which thepresent invention is applied is used for a table lamp which is alighting apparatus. The table lamp shown in FIG. 8 has a housing 2001and a light source 2002. The light-emitting device of the presentinvention is used for the light source 2002. Since the light-emittingdevice of the present invention has higher reliability and fewerdefects, the table lamp also has higher reliability and fewer defects.

FIG. 9 shows an example in which a light-emitting device to which thepresent invention is applied is used for an indoor lighting apparatus3001. Since the light-emitting device of the present invention can bemade to have a larger area, it can be used for a lighting apparatushaving a large emission area. Further, since the light-emitting deviceof the present invention is thin, the light-emitting device of thepresent invention can be used for a lighting apparatus having a thinnershape. In a room where a light-emitting device to which the presentinvention is thus applied is used for the indoor lighting apparatus3001, a television set 3002 according to the present invention asdescribed in FIG. 6A is placed, and public broadcasting and movies canbe enjoyed. In such a case, a powerful image can be watched in a brightroom.

This application is based on Japanese Patent Application serial no.2007-162046 filed with Japan Patent Office on Jun. 20, 2007, the entirecontents of which are hereby incorporated by reference.

1. A light-emitting device comprising: a light-emitting element over asubstrate, the light-emitting element being partitioned from an adjacentlight-emitting element by a partition wall, wherein the light-emittingelement comprises: a first electrode; a layer formed over the firstelectrode; a light-emitting layer formed over the layer; and a secondelectrode formed over the light-emitting layer, wherein the layercontains a transition metal oxide, an organic compound and a halogenatom, the organic compound being an aromatic amine compound or anaromatic hydrocarbon, wherein a top surface of the layer is aligned witha top surface of the partition wall, and wherein the partition wallcontains the transition metal oxide and the organic compound.
 2. Thelight-emitting device according to claim 1, wherein the layer has ahigher conductivity than the partition wall.
 3. The light-emittingdevice according to claim 1, wherein a difference between a filmthickness of the layer and a film thickness of the partition wall iswithin ±5% of the film thickness of the partition wall.
 4. Thelight-emitting device according to claim 1, wherein a concentration ofthe halogen atom contained in the layer is 1×10²¹ atoms/cm³ or more. 5.The light-emitting device according to claim 1, wherein a weight percentof the transition metal oxide in the layer is greater than or equal to5% and less than or equal to 25%.
 6. The light-emitting device accordingto claim 1, wherein the transition metal oxide is molybdenum oxide. 7.The light-emitting device according to claim 1, wherein the transitionmetal oxide is molybdenum trioxide.
 8. The light-emitting deviceaccording to claim 1, wherein the halogen atom is fluorine or chlorine.9. The light-emitting device according to claim 1, wherein each of afilm thickness of the layer and a film thickness of the partition wallis 500 nm or more.
 10. The light-emitting device according to claim 1,wherein the light-emitting device is incorporated in one selected fromthe group consisting of a television set, a computer, a cellulartelephone, a camera, a backlight of a liquid crystal display device, atable lamp and an indoor lighting apparatus.
 11. A light-emitting devicecomprising: a light-emitting element over a substrate, thelight-emitting element being partitioned from an adjacent light-emittingelement by a partition wall, wherein the light-emitting elementcomprises: a first electrode; a layer formed over the first electrode; alight-emitting layer formed over the layer; and a second electrodeformed over the light-emitting layer, wherein the layer contains atransition metal oxide, an organic compound and a halogen atom, whereina top surface of the layer is aligned with a top surface of thepartition wall, and wherein the partition wall contains the transitionmetal oxide and the organic compound.
 12. The light-emitting deviceaccording to claim 11, wherein the layer has a higher conductivity thanthe partition wall.
 13. The light-emitting device according to claim 11,wherein a difference between a film thickness of the layer and a filmthickness of the partition wall is within ±5% of the film thickness ofthe partition wall.
 14. The light-emitting device according to claim 11,wherein a concentration of the halogen atom contained in the layer is1×10²¹ atoms/cm³ or more.
 15. The light-emitting device according toclaim 11, wherein a weight percent of the transition metal oxide in thelayer is greater than or equal to 5% and less than or equal to 25%. 16.The light-emitting device according to claim 11, wherein the transitionmetal oxide is molybdenum oxide.
 17. The light-emitting device accordingto claim 11, wherein the transition metal oxide is molybdenum trioxide.18. The light-emitting device according to claim 11, wherein the halogenatom is fluorine or chlorine.
 19. The light-emitting device according toclaim 11, wherein each of a film thickness of the layer and a filmthickness of the partition wall is 500 nm or more.
 20. Thelight-emitting device according to claim 11, wherein the light-emittingdevice is incorporated in one selected from the group consisting of atelevision set, a computer, a cellular telephone, a camera, a backlightof a liquid crystal display device, a table lamp and an indoor lightingapparatus.
 21. A light-emitting device comprising: a light-emittingelement over a substrate, the light-emitting element being partitionedfrom an adjacent light-emitting element by a partition wall, wherein thelight-emitting element comprises: a first electrode; a layer formed overthe first electrode; a light-emitting layer formed over the layer; and asecond electrode formed over the light-emitting layer, wherein the layercontains a transition metal oxide, an organic compound and a halogenatom, the organic compound being an aromatic amine compound or anaromatic hydrocarbon, wherein the partition wall contains the transitionmetal oxide and the organic compound, and wherein a thickness of thepartition wall is equal to a sum of a thickness of the layer and athickness of the first electrode.
 22. The light-emitting deviceaccording to claim 21, wherein the layer has a higher conductivity thanthe partition wall.
 23. The light-emitting device according to claim 21,wherein a difference between a film thickness of the layer and a filmthickness of the partition wall is within ±5% of the film thickness ofthe partition wall.
 24. The light-emitting device according to claim 21,wherein a concentration of the halogen atom contained in the layer is1×10²¹ atoms/cm³ or more.
 25. The light-emitting device according toclaim 21, wherein a weight percent of the transition metal oxide in thelayer is greater than or equal to 5% and less than or equal to 25%. 26.The light-emitting device according to claim 21, wherein the transitionmetal oxide is molybdenum oxide.
 27. The light-emitting device accordingto claim 21, wherein the transition metal oxide is molybdenum trioxide.28. The light-emitting device according to claim 21, wherein the halogenatom is fluorine or chlorine.
 29. The light-emitting device according toclaim 21, wherein each of a film thickness of the layer and a filmthickness of the partition wall is 500 nm or more.
 30. Thelight-emitting device according to claim 21, wherein the light-emittingdevice is incorporated in one selected from the group consisting of atelevision set, a computer, a cellular telephone, a camera, a backlightof a liquid crystal display device, a table lamp and an indoor lightingapparatus.
 31. A light-emitting device comprising: a light-emittingelement over a substrate, the light-emitting element being partitionedfrom an adjacent light-emitting element by a partition wall, wherein thelight-emitting element comprises: a first electrode; a layer formed overthe first electrode; a light-emitting layer formed over the layer; and asecond electrode formed over the light-emitting layer, wherein the layercontains a transition metal oxide, an organic compound and a halogenatom, wherein the partition wall contains the transition metal oxide andthe organic compound, and wherein a thickness of the partition wall isequal to a sum of a thickness of the layer and a thickness of the firstelectrode.
 32. The light-emitting device according to claim 31, whereinthe layer has a higher conductivity than the partition wall.
 33. Thelight-emitting device according to claim 31, wherein a differencebetween a film thickness of the layer and a film thickness of thepartition wall is within ±5% of the film thickness of the partitionwall.
 34. The light-emitting device according to claim 31, wherein aconcentration of the halogen atom contained in the layer is 1×10²¹atoms/cm³ or more.
 35. The light-emitting device according to claim 31,wherein a weight percent of the transition metal oxide in the layer isgreater than or equal to 5% and less than or equal to 25%.
 36. Thelight-emitting device according to claim 31, wherein the transitionmetal oxide is molybdenum oxide.
 37. The light-emitting device accordingto claim 31, wherein the transition metal oxide is molybdenum trioxide.38. The light-emitting device according to claim 31, wherein the halogenatom is fluorine or chlorine.
 39. The light-emitting device according toclaim 31, wherein each of a film thickness of the layer and a filmthickness of the partition wall is 500 nm or more.
 40. Thelight-emitting device according to claim 31, wherein the light-emittingdevice is incorporated in one selected from the group consisting of atelevision set, a computer, a cellular telephone, a camera, a backlightof a liquid crystal display device, a table lamp and an indoor lightingapparatus.